Self-locking check arm



Dec. 2, 1941. KELLER 2,264,382

SELF-LOGKUIGYCHEGKARM Filed June so, 1957 2 sheets-sheet i De 2, 1941. A. KELLER SELF-LOCKING CHECK ARM Filed June 30, 1957 Z'Sheets-Sheet 2 IN VENTOR B fla usz /{aZZe/.

ATTORN 5.

Patented Dec. 2, 1941 SELF-LOCKING CHECK ARM August Keller, Dearborn,

Mich.,, assignor, by

mesne assignments, to Motor State Products Company, Ypsilanti, Mich a corporation of Michigan 4 Claims.

This invention relates to self-locking check arms used in connection with two separable members for the purpose of locking the same in a predetermined space relationship. More partic ularly the invention contemplates providing a self-locking check arm adapted to be used in connection with hinged lids or covers such, for example, as the cover of the rear compartment of an automobile.

One of the objects of the present invention is to provide an improved check arm which looks itself automatically in a plurality of successive positions corresponding to various degrees of opening of a lid or cover of a receptacle or of a compartment.

Another object of the invention is to provide an improved, positively acting, self-locking check arm in which the number of parts is reduced to a minimum, thus reducing the possibility of failure of the check arm because of defects in assembly or because of separation of the parts.

A further object of the invention is to provide a check arm which has a plate with a plurality of slots .01 ways forming a broken line path for the follower, said plate being manufactured in a single piece by stamping operations. In this connection it is well known in the art that forming such plate by milling out the slots is a tedious and expensive operation and that forming the plate by riveting separate properly spaced pieces or islands to a thin plate is objectionable because of the frequent failures of arms resulting from the shearing ofi of the rivets and consequent separation of such islands from the plate.

It is an added object of the invention to provide an improved self-locking check arm of the foregoing character which is simple in construction and dependable in operation, and which is relatively inexpensive to manufacture.

Other objects of this invention will appear in the following description and appended claims, reference being had to the accompanying drawings forming a part of this specification wherein like reference characters designate corresponding parts in the several views.

Fig. 1 is a perspective view of the rear portion of a motor vehicle having a hinged lid provided with a self-locking check arm constructed in accordance with the present invention.

Fig. 2 is a side view of the structure shown in Fig. l, the view being taken on the line 2--2 of Fig. 1.

Fig. 3 is a view taken on the line 33 .of Fig. 2.

Fi 4 is a e vation wi h parts brokenaw yy taken substantially on the line 4-.4 in the direction of the arrows, Fig. 3.

Fig. 5 is a sectional view in the direction of the arrows, the section being taken on the line 55 of Fig. 4.

Fig. 6 is a transverse sectional view in the direction of the arrows, the section being taken on the line 6-6 of Fig. 5.

Fig. 7 is a fragmentary perspective view illustrating cooperation of the slotways and the follower, the latter being shown approaching the end of the main slot.

Fig. 8 is a view similar in part to that of Fig. 7, the follower being shown in the return slot.

Fig. 9 is a diagrammatic view showing the arrangement of the islands and of the slots formed thereby.

Before explaining in detail the present invention it isto be understood that the invention is not limited in its application to the details of construction and arrangement of parts illustrated in the accompanying drawings, since the invention is capable of other embodiments and of being practiced or carried out in various ways. Also it is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation, and it is-not intended to limit the invention claimed herein beyond the requirements of the prior art.

In the drawings there is shown, by way of example, a self-locking check arm constructed in accordance with one embodiment of the present invention and applied to the hinged lid of the rear compartment of a motor vehicle. Referring to Figs. 1 and 2, l0 indicates a motor vehicle of a conventional design having a rear compartment ll adapted to be closed with a lid or cover l2 connected to the motor vehicle by means of hinges L3. The cover I2 is adapted to be opened as shown in Fig. l, in order to permit access to the rear compartment, and to be closed in order to cover the same. The provision of the check arm on the lid [2 is desirable in order to lock the cover l2 automatically in its open position. In accordance with the invention the cover l2 may be locked in a plurality of open positions, thus permitting 1 various degrees of opening of the cover l2.

The self-locking check arm comprises two telescoping members l5 and Hi. The member I5 is connected by means of a pivot l8 to the bracket 11 secured to the lid I2. The member 16 is secured to the bracket I9 fixed to the motor vehicle structure. A pin or pivot 20 connects said bracket l9 and the member IS. The meme bers I5 and I6 are of a channel cross section, member I 5 being adapted to fit into the member I5 which member is provided with flanges 22 whereby the member I5 is retained in telescoping relation within the member I6, as best shown in Figs. 2 and 6. The length of the stroke of the telescoping member I5 is represented by the distance between the center of the pin I8 and the point 23 (Fig. 2), it being understood that the distance between the centers of the pins and I8 represents the distance between said pins in the fully extended position of the check arm. The distance between the pin 20 and the point 23 represents the distance between said pins in the fully contracted position of the check arm. An arm 24 is connected to the member I6 by means of a hinge or pivot 25, said arm preferably being of a flat tapering shape. A follower 25 is provided at the end of the arm opposite to the hinge carrying end, and extends on a line transverse to the plane of the arm. The arm 24 is free to rotate around the hinge 25, said rotation being restrained only by the walls of the channel members and by the means engaging the follower 26.

At the bottom of the channel member I5 there is provided a plate 2'! welded or otherwise secured to the member 15. On the plate 21 there is provided a plurality of raised portions or islands which form, together with the walls of said member 15, three parallel slo'tways connected by means of transversely extending ways. For the purpose of description said parallel slots are indicated in Fig. 4 by the numerals 28, 29 and 30, while the raised portions or islands are indicated respectively by the numerals 3|, 32, 33, 34, and 36. The slotway 28 is termed the main or first slot, the slot 29 the intermediate or second slot, and the slot 35 the return or the third slot.

The raised portions or islands are provided with cam portions and with looking portions and are so located in the respective slots that cooperating with the follower 25 they permit locking the cheek arm in three positions and permit unlocking the check arm and closing the cover without the necessity of carrying the same through the succeeding locking position.

When the check arm is in its fully contracted position, the follower 26 is in the position indicated in Fig. 4 by the numeral 31. It will be noticed that in the fully closed or contracted position of the check arm the follower 26 may be either in the slot 23 or in the slot 29. Assuming the follower 25 to be in the slot 28, it will be understood that as the cover I2 is moved toward its open position, the follower 25 moves in the direction of the island 32 and comes into the position indicated by the numeral 38. When this position is reached, the action of the cam portion 39 of the island 32 operates to guide the follower 25 into the position in the intermediate slot 29 indicated by the numeral 40. If the opening movement of the cover i2 is continued, the follower 26 moves from the position 40 into the position 42 in said intermediate slot 29, thereby contacting the cam portion 42 of the island 43. Further movement of the follower causes it to be guided by the cam portion 42 of the island 33 from the intermediate slot into the main slot 28, bringing it into the position 43. If the closing movement of the cover I2 is now attempted, the follower 26 will move from the position 43 into the position 44, contacting the locking portion provided on the island 32. The position 44 represents the first locking position of the follow- If, however, the opening movement of the cover continues, the follower moves from the first locking position 44 through the position 43 into the position 45 in which it contacts the cam portion 41 provided on the island 34. Continued opening movement of the cover will operate, because of the guiding action of the cam 41, to bring the follower 25 into the position 48 in the intermediate slot 29. The follower will now move into the position 49 contacting the cam portion 56 provided on the pilot 35 and will be guided by said cam portion back into the main slot 28 and brought into the position indicated by the numeral 5|. If the return or closing movement of the cover is attempted at this point, the follower 23 will move into the position 52, contacting the locking portion 53 provided on the island 34. Position 52 is the second locking position of the follower. The opening movement of the follower from the position 52 will carry the follower 26 through the position 5% into the position 54 in which the follower contacts the cam portion 55 provided on the island 35, which portion will 0perate to guide the follower into the position 56 in the first half of the intermediate slot 29. The position 55 is the extreme open position of the follower. For locking the lid or cover in this position, the cover is let down and it moves under its own weight carrying the follower 26 into the position 5'! in which the follower contacts the cam portion 58 provided on the island 35. The cam portion 58 guides the follower into the position indicated by the numeral 59, which position constitutes the third locking position of the arm.

For closing the cover the same is slightly raised to unlock the arm 24, the raising movement of the cover operating to bring the follower 29 into the position 60 in which the same contacts the cam portion SI provided on the island 38, which portion guides the follower 25 from the second half of the slot 29 into the return slot 30, the position of the follower in said slot being indicated by the numeral 52. It is important to note that the follower 26 is slanted or rounded in order to facilitate operation of the cam portion BI. It should also be noted that the transverse dimension of the follower is preferably equal to substantially one-half of the width of the intermediate slot. It will also be noted that the cam portion GI commences approximately in the middie of the intermediate slot 29.

When the follower 26 is brought into the position 62, it may be moved without interference along the return slot 39 through the position 63 into the position 64, where the follower contacts the cam portion 65 provided on the island 3I. The cam portion 65 operates to guide the follower into the position 66 in the return slot, and when the cover is entirely closed the follower moves into the position 61. At this point the follower possesses or is permitted a certain amount of play and may be in position Bl or position 31. From the position 51 or 31 the follower may again go through the above described sequence of movements.

It should be noted that from the locking position 44 the follower may be moved into the return slot without bringing the same into the suc ceeding locking position. The same may be effected by slightly raising the cover to carry the follower through the positions 43, 45 and 48. The downward movement of the cover 52 with the follower in the position 48 will carry the follower into the position indicated by the numeral 69 where the follower contacts the cam portion 69 provided on the island 33. The cam portion 69 guides the follower into the position 63 in the return slot 39. From this position the follower may be moved into the position 64 and to the position 65 into the initial position 6? or 37, thus completing the operation cycle.

It is an important feature of the present invention that the plate 21 and the islands as shown are formed in a single stamped metal part. Therefore, the manufacture of the arm is very accurate yet simple and relatively inexpensive. Since failures of check arms may be due to the separation of the islands from the channel member when they are secured thereto by means of rivets, or by mistakes in the location of the islands or forming of the slotways, it will be seen that the present invention produces a superior check arm in which the common causes of failure are eliminated. Assembly of the check arm is simple and fast since the entire island and slotway assembly is secured to the arms in a single operation and may be secured thereto as by welding or other selected means. In addition, locations of the islands and slotways and the guiding characteristics thereof are exact, since positioning of islands in a stamped piece is exact and constant. Where positioning of the islands or raised portions is determined by the positions of respective rivet holes, it is difiicult to maintain an exact and constant location of the parts and a careful layout is necessary in order to achieve location of the islands to provide a satisfactory device.

Provision of the three locking positions of the follower also provides an important, convenient and safety feature which is effected without requiring the use of additional moving parts in the check arm.

I claim:

1. In a self-locking check arm, two telescoping channel members, an arm hinged to one of said members, a depending cam member secured to the swinging end of said arm, a plate secured to the other of said members and formed to provide a plurality of integral islands and slotways therein adapted to contact and guide said cam member during relative movement of said channel members, said islands being so shaped and spaced as to form three parallel slotways forming a cyclic broken line path, the first of said slotways being interrupted by three cam portions formed on said islands, each of said portions operating during the opening movement of said telescoping member to direct the depending cam member from said first slotway into the intermediate slotway, and a plurality of islands in said intermediate slotway having cam portions arranged to direct said depending cam member into said first slotway and into engagement with a portion of a selected island therein to lock said channel members against a closing telescoping movement at a plurality of points in said first slotway.

2. In a self-locking check arm, two telescoping channel members, an arm hingedly secured to one of said members, a follower secured to the swinging end of said arm, a plurality of islands formed on the other member to define three adjacent interconnected slotways adapted to receive said follower and direct it through a cyclic path during relative movement of said channel members, three islands formed in the first of said slotways, all of said three islands having cam surfaces arranged to guide the follower from said first slotway into the intermediate slotway as the telescopic members are moved toward their extended positions, two of said islands having stop portions engaging said follower to prevent unintended movement of the telescoping members toward their contracted positions, two islands provided in the intermediate slotway and spaced relative to the islands in the first slotway having said stop portions thereon, the islands in the intermediate slotway each having a cam surface arranged, to guide the follower into locking position on one of said islands in said first slotway during the extension movement of the telescoping members to lock said members against closing movement in a plurality of positions during the normal opening cycle thereof.

3. In a self-locking check arm, two telescoping channel members, an arm hinged to one of said members, a depending cam member secured to the swinging end of said arm, a plate secured to the other of said members and formed to provide a plurality of integral islands and slotways therein adapted to contact and guide said cam member during relative movement of said channel members, said islands being so shaped and spaced as to form three parallel slotways forming a cyclic broken line path, the first of said slotways being interrupted by three cam portions formed on said islands, each of said portions operating during the opening movement of said telescoping member to direct the depending cam member from said first slotway into the intermediate slotway, a plurality of islands in said intermediate slotway having cam portions arranged to direct said depending cam member into said first slotway and into engagement with a portion of a selected island therein to lock said channel members against a closing telescoping movement at a plurality of points in said first slotway, and an end member having cam surfaces adapted to contact said follower and to direct said follower into a third slotway for unimpeded return of the parts to their closed positions.

4. In a self-locking check arm, two telescoping channel members, an arm hingedly secured to one of said members, a follower secured to the swinging end of said arm, a plurality of islands formed on the other member to define three adjacent interconnected slotways adapted to receive said follower and direct it through a cyclic path during relative movement of said channel members, three islands formed in the first of said slotways, all of said three islands having cam surfaces arranged to guide the follower from said first slotway into the intermediate slotway as the telescopic members are moved toward their extended positions, two of said islands having stop portions engaging said follower to prevent unintended movement of the telescoping members toward their contracted positions, two islands provided in the intermediate slotway and spaced relative to the islands in the first slotway having said stop portions thereon, the islands in the intermediate slotway each having a cam surface arranged to guide the follower into locking position on one of said islands in said first slotway during the extension movement of the telescoping members to lock said members against closing movement in a plurality of positions during the normal opening cycle thereof, and an end member having cam surfaces adapted to contact said follower and to direct said follower through a third slotway for unimpeded return of the parts to their closed positions.

AUGUST KELLER. 

